What is a cipher? According to Wikipedia (1), it is an algorithm for performing
encryption or decryption -- a series of well-defined steps that can be followed as a
procedure. Another way to think about this is that it is a process of taking text
through steps to change it. Also, when working with symmetric ciphers, the inverse
of the process will convert the message back to the original text. Below are the
characteristics of the three symmetric encryption ciphers up for discussion.
Character
oSubstitution or shifting is done one character at a time
oROT13, also known as the Caesar Cipher, is my favourite one which shifts
13 characters to the right on the alphabet (2)
oThe simplest of the three
